7: Biochemistry - Lipid anabolism

Question 1

In lipid metabolism, dietary energy is converted into stored ___.

Answer 1

fat

Question 2

What is lipogenesis?

Answer 2

Fatty acid synthesis

Question 3

Lipogenesis takes place during (insufficient / excess) energy intake.

Answer 3

excess

Question 4

In lipogenesis, carbohydrate is converted to which lipids?

Answer 4

Fatty acids

Triglycerides

Question 5

Which molecule carries triglycerides to adipose tissue?

Answer 5

VLDL

Question 6

Which protein carries free fatty acids in the plasma?

Answer 6

Albumin

Question 7

Where does lipogenesis primarily occur?

Answer 7

Liver

Question 8

Lipogenesis is a (oxidative / reductive) process.

Answer 8

reductive

Question 9

What is the precursor molecule for lipogenesis?

Answer 9

Acetyl-CoA

Question 10

Fatty acid breakdown to Acetyl-CoA occurs in the (cytoplasm / mitochondrial matrix).

Fatty acid synthesis from Acetyl-CoA occurs in the (cytoplasm / mitochondrial matrix).

Answer 10

mitochondrial matrix

cytoplasm

Question 11

Which molecule, usually generated in the TCA cycle, transports acetyl groups into the cytoplasm?

Answer 11

Citrate

Question 12

Before Acetyl-CoA can convert lipids to carbohydrate, it has to be activated. Which enzyme activates Acetyl-CoA?

Answer 12

Acetyl-CoA carboxylase

Question 13

What is formed by the activation of acetyl-CoA by acetyl-CoA carboxylase?

Answer 13

Malonyl-CoA

Question 14

What is the essential regulatory enzyme for the first step of lipogenesis?

Answer 14

Acetyl-CoA carboxylase

Question 15

What is the activated form of acetyl-CoA which donates a carbon atom to the lipid?

Answer 15

Malonyl-CoA

Question 16

Which enzyme catalyses the synthesis of long chain fatty acids from malonyl-CoA, acetyl-CoA and NADPH?

Answer 16

Fatty acid synthase

Question 17

Which protein carries the growing fatty acid chain until sufficient carbon atoms have been added to it?

Answer 17

Acyl-carrier protein (ACP)

Question 18

What donates electrons to the growing fatty acid chain during lipogenesis?

Answer 18

NADPH

Question 19

When the length of __ carbons is reached, the newly synthesised fatty acid is released from ACP.

Answer 19

16

Question 20

What is the regulatory enzyme in lipogenesis?

Answer 20

Acetyl-CoA carboxylase

Question 21

Which hormone, which signals the fed state, stimulates the activity of acetyl-CoA carboxylase?

Answer 21

Insulin

Question 22

Which hormone, which signals the starved state, inhibits the activity of acetyl-coA carboxylase?

Answer 22

Glucagon

Question 23

What is a hormone, other than glucagon, which inhibits the action of acetyl-CoA carboxylase and therefore lipogenesis?

Answer 23

Adrenaline

Question 24

The concentration of which molecule acts allosterically to switch off lipogenesis when it is high?

Answer 24

Citrate

Question 25

Which activated form of glycerol is required for triglyceride synthesis?

Answer 25

Glycerol-3-phosphate

Question 26

In which form is fat stored in adipose tissue?

Answer 26

As triglycerides